Induction of HIV-1 Env-Specific Peripheral Blood Plasmablasts and Clonal Persistence as Bone Marrow Plasma Cells Following Vaccination in Humans

Induction of persistent HIV-1 Envelope (Env) specific antibody (Ab) is a primary goal of HIV vaccine strategies, however, it is unclear if HIV Env immunization in humans induces bone marrow plasma cells, the presumed source of long-lived systemic Ab. To define the features of Env-specific plasma cells after vaccination, samples were obtained from HVTN 105, a phase I trial testing the same gp120 protein immunogen, AIDSVAX B/E, as used in RV144, along with a DNA immunogen in various prime/boost strategies. Boosting regimens that included AIDSVAX B/E induced robust peripheral blood plasmablast responses. The Env-specific immunoglobulin repertoire of the plasmablasts was dominated by VH1 gene usage and targeting of the V3 region. Numerous plasmablast-derived immunoglobulin lineages persisted in the bone marrow greater than eight months after immunization, including in the CD138+ long-lived plasma cell compartment. These findings identify a cellular linkage for the development of sustained Env-specific Ab following vaccination in humans.]]>